MAX3421E USB Host IRQ Issue

[jbaum81]

Hi guys,

Taking my first adventure down the USB Rabbit hole with the Max3421 setup as host. I'm currently running into an issue where the controller is constantly throwing Peripheral connect/disconnect interrupts while the bus is in the SE0 state. The data sheet says it should only flag the interrupt after going from J or K to SE0 for x ms or vice versa. Going from SE0 to J or K flags an interrupt, I ack and it stays gone. The opposite is not true. I do have the pulldowns enabled for both lines in register 27. Register 18 reports a revision of 0x13. Any help would be appreciated.

[jbaum81]

Figured it out. I had it set to high speed and SOF frames auto generating which was causing the irq. When I detect a bus event and no J/K state now I'm turning it off until the next bus event and all is well. Well, I'm writing a USB driver in 6502 assembly for USB, as well as can be expected.